Cocktail of noxious gases turns up the heat,says study

Ozone — not the atmospheric layer that protects us from ultraviolet radiation — but a hovering pollutant created in summer by the steady mix of hydrocarbons and nitrogen oxides (Nox),is on the rise in Delhi.

Data collected by the Central Pollution Control Board (CPCB) and analysed by the Centre of Science and Environment (CSE) shows that ozone levels peak in the city with heat.

Ozone remains an overlooked,but dangerous pollutant. The Delhi Pollution Control Committee (DPCC) does not monitor ozone levels in the Capital at all. Meanwhile,parent body CPCB monitors different pollutants like NOx,sulphur dioxide,suspended particulate matter (SPM),respirable SPM and carbon monoxide at 40 different places in the city. But ozone levels are monitored only at three places — ITO,Siri Fort and Bawana.

The data analysis has found that in the cold month of January,ozone levels remained below 90 milligrams per metre cube (which is the proposed standard),but as the heat increased,it picked up. “Between May 1 and 9,the ozone levels were between 120 mg/metre cube and 192 mg/m3. On March 22,the level at Siri Fort was 199 mg/m3,” says Anumita Roychowdhary,the chief of the air pollution department at CSE.

Ozone works differently from other pollutants. “The worrying thing is that unlike other pollutants,even a few hours of exposure to ozone — which is basically a cocktail of noxious gases — can cause serious damage. Ozone is like an oxidiser that corrodes cells. Inhalation could even increase heart disease and emphysema (lung disease),besides triggering asthma,” Roychowdhary adds. She says athletes who will come in for the Commonwealth Games may be victims to high levels of ozone.

“Athletes inhale pollutants 20 times more than sedentary people. And though it may not be very hot in October (when the Games will be held),it might still be sunny enough for a high-level build-up. We need better understanding of this pollutant. This can only be done through increased monitoring,” the environmentalist says.

The government says it will consider studying ozone seriously if reports and research on its impact comes its way. “The DPCC does not monitor ozone levels; however,that does not mean we don’t recognise it as a pollutant. Monitoring also requires better machinery. If we are presented with reports on this pollutant,we shall be open to studying and monitoring this pollutant,” says Dr A K ambasht,Member Secretary,DPCC.